Abstract: This disclosure provides fire retardant materials, including polymers that include at least one pyridinium salt moiety and at least one phosphine oxide moiety.

Abstract: This disclosure provides fire retardant materials, including polymers that include at least one pyridinium salt moiety and at least one phosphine oxide moiety.

Abstract: This document provides fire retardant materials, including polymers that include pyridinium salt moieties, or a combination thereof, and phosphine oxide moieties. In some cases, fire retardant polymers provided herein have the following structure: where R1 and R6 are each selected consisting of N, wherein R2 and R7 are each negatively charged counterions, where R3, R4, R8, R9, R11, R13, R14, R15, and R16 are each H or a group including one or more carbon molecules, and where R5, R10, and R12 are each groups including one or more carbon molecules.

Abstract: This document provides fire retardant materials, including polymers that include pyridinium salt moieties, or a combination thereof, and phosphine oxide moieties. In some cases, fire retardant polymers provided herein have the following structure: where R1 and R6 are each selected consisting of N, wherein R2 and R7 are each negatively charged counterions, where R3, R4, R8, R9, R11, R13, R14, R15, and R16 are each H or a group including one or more carbon molecules, and where R5, R10, and R12 are each groups including one or more carbon molecules.

Abstract: A solid state optical sensor for CO has a sensing material which includes a molybdenum, tungsten or vanadium color forming agent; a palladium, ruthenium or osmium catalyst; and an iron, chromium or cesium reversing agent. A redox property modifier and/or an interference suppressing agent may also be included. The chemistry is contained in a polymer embedding matrix, with permeation enhancer, if required. Solubility of the chemistry in the polymer matrix is enhanced by lipophilic counterions. The matrix with embedded sensing chemistry is coated on an optical substrate to form an optical transducer.

Abstract: A sensing chemistry for halogenated hydrocarbons includes pyridine or a pyridine derivative and a strong organic alkoxide base. The sensing chemistry may be in a nonaqueous organic solvent or in a solid state matrix. The base reacts with the halohydrocarbon to produce a carbene intermediate reaction product, which in the absence of water preferentially reacts with the pyridine to form a colored and/or fluorescent product.

Abstract: A molybdenum, tungsten or vanadium salt-palladium, ruthenium or osmium salt solution for CO detection is made reversible by addition of ferric, chromium (VI) or cerium (IV) ion. The system is made more CO specific by adding an interference control salt which forms white or colorless precipitates with interfering species. The operational and shelf life are extended by a mixture of counterions; the acetate counterion is particularly useful.

Abstract: A molybdenum salt-palladium salt solution for CO detection is made reversible by addition of ferric ion. The system is made more CO specific by adding an interference control salt which forms white or colorless precipitates with interfering species. The operational and shelf life are extended by a mixture of counterions; the acetate counterion is particularly useful.

Abstract: A fiber optic chemical sensor is made water repellent by attaching a plurality of long, hydrophobic chains, e.g. silane polymers, to the surface. The chains extend from the surface and form a semi-permeable barrier which repels water molecules while selectively passing analyte molecules therethrough. In one configuration, the hydrophobic chains are attached substantially uniformly over the clad. In a second configuration, the clad is a plurality of spaced stripes with the hydrophobic chains attached in the gaps between the stripes. In another configuration, a patterned hydrophobic coating of alternating thick and thin segments is formed on the clad.

Abstract: A chemical sensor, such as a fiber optic chemical sensor, is self-calibrated by measuring two output values which behave differently in response to an analyte, and forming a ratio between the two measured output values to cancel out effects of variations in external factors such as temperature variations, differences between coatings, light (illuminator) variations, fouling, bleaching, leaching or the like. An indicator material may be used which produces both fluorescence and phosphorescence, both monomer and aggregate emission or absorption bands, emission or absorption bands with or without an isosbestic point, emission peaks at one wavelength at two different excitation bands, or emission peaks at two wavelengths for excitation at two wavelengths.

Abstract: Single and multi-cell reservoir FOCS configurations, with single or dual fibers with optional optical elements, have a cross-flow arrangement of the sample relative to the fiber. A wide variety of sensors, including pH, arsenic, benzene, cyanide, hydrazine, cupric ion; TCE, mercuric ion, and iron(2+) are provided.

Abstract: A refractive index FOCS has a fiber optic core with a partly light transmissive thin metal film clad of an effective thickness and light transmissivity so that transmission through the core is strongly affected by the refractive index of a surrounding liquid or vapor medium. The metal clad and surrounding medium produce a localized refractive index at the core interface which modulates light transmission through the core as a function of the medium refractive index. The clad is made of platinum, or also of gold, rhodium, palladium, nickel, iron, cobalt, ruthenium, iridium, osmium, zinc, copper, silver, chronium, molybdenum, tungsten, vanadium, niobium, tantalum, titanium, zirconium or hafnium. The clad is also made of oxides of these metals, or metal compounds or alloys. With a fluorescent tip, the changes in the fluorescent signal are a measure of the medium refractive index. With a reflective tip, the changes in the reflected signal are measured.

Abstract: A refractive index FOCS has a thin metal film clad on a fiber optic core so that transmission through the core is strongly affected by the refractive index of a surrounding solvent. The clad is made of platinum, or also of gold, rhodium or palladium. With a fluorescent tip, the changes in the fluorescent signal are a measure of the solvent refractive index. With a reflective tip, the changes in the reflected signal are measured. In a linear configuration, source and detector are placed at opposite ends of the fiber and changes in the transmitted signal are measured as a function of solvent refractive index.

Abstract: A reservoir fiber optic chemical sensor (FOCS) is formed of a modular cell body. A fiber optic is attached using a quick connect standard fiber optic connector. A semipermeable membrane is attached at the opposite end of the cell body using a quick attach membrane retainer. Multiple sensors can be made uniformly. Specific sensors for TCE vapor, O.sub.2 and CO.sub.2 are produced by utilizing a suitable reaction chemistry in the cell. A non-imaging optical focusing element can be included in the cell to increase sensitivity. A reaction cell can be placed adjacent to the reservoir cell with the semi-permeable membrane separating the two cells to produce a photolysis FOCS. TOC and TOCl can be detected with the photolysis FOCS.

Abstract: A modular fiber optic chemical sensor (FOCS) is formed using a capillary tube clad. A fiber optic core with reactive surface is exposed to a sample environment and then the capillary tube is fitted over the core. The capillary could also be porous so that in-situ measurements can be made. The capillary can be spaced from the core so that a flow channel for gas and liquid sensing is formed, or an index matching fluid may fill the channel. Measurements can be made in a compact portable modular detector unit in which the FOCS is placed between an excitation source and a detector or single ended where the excitation source and detector are at the same end of the core and a reflector is placed at the end of the core.